Shaft Seal Assembly

ABSTRACT

A method for maintaining a seal during shaft misalignment using a shaft seal assembly comprising a first sealing means adjacent said shaft with a defined clearance between said shaft and said sealing means, said shaft moveable axially in relation to said first sealing means; a second sealing means, said first sealing means partially encompassed within second sealing means and in cooperative communication with said second sealing means; a third sealing means, said second sealing means partially encompassed within third sealing means and in cooperative communication with said third sealing means, said third sealing means attached to said housing or vessel and allowing said first sealing means and second sealing means to cooperatively respond to said forces produced by angular misalignment of said shaft during rotation of said shaft while maintaining defined clearance between said shaft and said sealing means.

CROSS REFERENCE TO RELATED APPLICATIONS

Applicant states that this utility patent application claims priorityfrom U.S. patent application Ser. No. 12/612,244 filed on Nov. 4, 2009and is a continuation of said utility patent application, which claimpriority from U.S. patent application Ser. No. 12/156,476 filed on May30, 2008 and was a continuation of said utility patent application,which claimed priority from U.S. patent application Ser. No. 11/405,207filed on Apr. 17, 2006, which claimed priority from both U.S. patentapplication Ser. No. 10/177,067 filed on Jun. 21, 2002 and ProvisionalPat. App. No. 60/697,434 filed on Jul. 9, 2005, all of which areincorporated by reference herein in their entireties.

FIELD OF THE INVENTION

The present invention relates to a shaft seal assembly with multipleembodiments. A labyrinth seal for retaining lubrication solution withinthe bearing cavity of a hub assembly, such as a bearing housing, forapplication to a rotatable shaft to keep contaminants out of the bearingcavity is disclosed and claimed. In another embodiment, the shaft sealassembly may be used as a product seal between a product vessel and ashaft therein.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

No federal funds were used to create or develop the invention herein.

REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTINGCOMPACT DISK APPENDIX

N/A

BACKGROUND OF THE INVENTION

For years there have been a multitude of attempts and ideas forproviding a satisfactory seal when a rotatable shaft is angularlymisaligned resulting in run out of the shaft. Typically the solutionspresented have failed to provide an adequate seal while allowing for anacceptable amount of shaft misalignment during operation. The problem isespecially acute in product seals where the potential for shaft to boremisalignment may be maximized. A typical solution in the prior art is toincrease the operating clearance between the rotating shaft and sealingmembers to create a “loose” clearance or operating condition. “Loose”running for adjustment or response to operational conditions, especiallymisalignment of the shaft with respect to the stator or stationarymember, however, typically reduces or lowers the efficiency and efficacyof sealing members.

Labyrinth seals, for example, have been in common use for many years forapplication to sealing rotatable shafts. A few of the advantages oflabyrinth seals over contact seals are increased wear resistance,extended operating life and reduced power consumption during use.Labyrinth seals, however, also depend on a close and defined clearancewith the rotatable shaft for proper function. Shaft misalignment is alsoa problem with “contact” seals because the contact between the seal andmisaligned shaft typically results in greater wear. Abrasiveness of theproduct also affects the wear pattern and the useful life of the contactseals.

Prior attempts to use fluid pressure (either vapor or liquid) to sealboth liquid and solid materials in combination with sealing members suchas labyrinth seals or contact seals have not been entirely satisfactorybecause of the “tight” or low clearance necessary to create the requiredpressure differential between the seal and the product on the other sideof the seal (i.e., the tighter the seal, the lower the volume of fluidrequired to maintain the seal against the external pressure ofmaterial.) Another weakness in the prior art is that many product sealsexpose the movable intermeshed sealing faces or surfaces of the productseal to the product resulting in aggressive wear and poor reliability.Furthermore, for certain applications, the product seal may need to beremoved entirely from the shaft seal assembly for cleaning, because ofproduct exposure to the sealing faces or surfaces.

The prior art then has failed to provide a solution that allows both a“tight” running clearance between the seal members and the stationarymember for efficacious sealing and a “loose” running clearance foradjustment or response to operational conditions especially misalignmentof the rotatable shaft with respect to the stator or stationary member.

SUMMARY OF THE INVENTION

The present art offers improved shaft sealing and product sealperformance over the prior art. The shaft seal assembly solutiondisclosed and claimed herein allows both tight or low running clearancebetween seal members and the stationary member and a loose runningclearance for adjustment or response to operational conditionsespecially misalignment of a rotatable shaft with respect to the statoror stationary member.

As disclosed herein, the present art describes and provides for improvedfunction by allowing a labyrinth seal to adjust to radial, axial andangular movements of the shaft while maintaining a desiredshaft-to-labyrinth clearance. The present art also permits equalizationof pressure across the labyrinth pattern by permitting venting and thusimproved function over currently available designs. Additionally,sealing fluid (air, steam, gas or liquid) pressure may be appliedthrough the vent or port locations to establish an internal sealpressure greater than inboard or outboard pressure(over-pressurization). This enables the labyrinth to seal pressuredifferentials that may exist between the inboard and outboard sides ofthe seal. Pressurization of the internal portion of the shaft sealassembly effectively isolates the moving or engaging faces of the shaftseal assembly from contact with product by design and in combinationwith a pressurized fluid barrier.

It is therefore an object of the present invention to provide a shaftseal assembly for engagement with a housing which maintains its sealingintegrity with a shaft upon application of axial, angular or radialforce upon said shaft.

It is another object of the present invention to provide a shaft sealassembly, which may be mounted to a vessel wall for engagement with ashaft which maintains its sealing integrity with a shaft during or inresponse to axial, angular or radial force movement of said shaft.

Other objects and features of the invention will become apparent fromthe following detailed description when read with reference to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective exterior view of the shaft seal assembly.

FIG. 2 is an exterior end view of the shaft seal assembly with the shaftelement aligned.

FIG. 3 is a sectional view of a first embodiment of the shaft sealassembly, as shown in FIG. 2 and mounted to a housing.

FIG. 3A illustrates the first surface seal-shaft integrity duringangular and radial shaft alignment.

FIG. 3B illustrates second surface seal-shaft integrity during angularand radial shaft alignment.

FIG. 4 is an exterior end view with the shaft misaligned.

FIG. 5 is a sectional view of the first embodiment as shown in FIG. 3with both angular and radial misalignment of the shaft applied.

FIG. 5A illustrates first seal-shaft integrity allowed by articulationduring angular and radial shaft misalignment.

FIG. 5B illustrates second seal-shaft integrity allowed by articulationduring angular and radial shaft misalignment.

FIG. 6 is a sectional view of a second embodiment of the shaft sealassembly as shown in FIG. 2.

FIG. 7 is a sectional view of a third embodiment as shown in FIG. 2.

FIG. 8 is a perspective view of a fourth embodiment as mounted to avessel wall.

DETAILED DESCRIPTION Element Listing

Description Element No. Shaft  1 Fixed stator  2 Fixed stator(part-line)  2a Labyrinth seal  3 Radiused face  3a Floating stator  4Fluid return pathway  5 Shaft seal clearance  6 First o-ring  7Anti-rotation pin  8 Vent  9 Anti-rotation groove (floating stator) 10Spherical interface 11 Anti-rotation pin 12 Second o-ring 13 Labyrinthseal pattern grooves 14 First o-ring channel 15 Cavity for anti-rotationdevice (fixed stator) 16 Axial face of labyrinth seal 17 Axial face offloating stator 18 Second o-ring channel 19 First clearance betweenfloating stator/fixed stator 20 Second clearance between floatingstator/fixed 21 stator Throttle groove 22 Labyrinth pattern annulargroove 23 Sleeve 24 Shaft seal assembly 25 Throttle (alignment skate) 26Floating stator annular groove 27 Labyrinth seal passage 28 Floatingstator passage 29 Housing 30 Angle of misalignment 31 Bearings andbearing cavity 32 Mounting bolts 33 Vessel wall 34

FIGS. 1-5 provide a view of a first embodiment of the shaft sealassembly 25 that allows for sealing various lubricating solutions withinbearing housing 30. FIGS. 6 and 7 provide alternative embodiments of theshaft seal assembly 25 wherein sealing fluids are used. Applicant hereindefines sealing fluids to include both liquids and vapors. Applicantconsiders air, nitrogen, water and steam as well as any other fluidwhich may work with the proposed shaft seal assembly to provide apressurized fluid barrier for any and all embodiments disclosed hereinto be within the purview of the present disclosure. The gas or fluidchosen is based on process suitability with the product to be sealed.

FIG. 1 is a perspective exterior view of the shaft seal assembly 25arranged and engaged with a shaft 1 inserted through the fixed stator 2of shaft seal assembly 25. FIG. 2 is an exterior end view of the shaftseal assembly with shaft 1 aligned within the shaft seal assembly 25.

FIG. 3 is a sectional view of a first embodiment of the shaft sealassembly 25 shown in FIG. 2 illustrating the shaft seal assembly 25 as alabyrinth seal for retaining lubrication solution within the bearingcavity 32 of housing 30. The shaft 1 shown in FIG. 3 is the type whichmay experience radial, angular or axial movement relative to the fixedstator element or portion of the fixed stator 2 during rotation. Thefixed stator portion of the shaft seal assembly 25 may be flange-mountedor press-fit or attached by other means to a housing 30. The inventionwill also function with a rotating housing and stationary shaft. (Notshown) As required by the particular application, the shaft 1 is allowedto move freely in the axial direction in relation to the shaft sealassembly 25.

A labyrinth seal 3 having an interior surface is engaged with shaft 1. Adefined clearance 6 exists between the interior surface of saidlabyrinth seal 3 and the shaft 1. Opposite the interior surface of saidlabyrinth seal 3 is the radiused surface 3 a of said labyrinth seal 3.The radiused surface 3 a of the labyrinth seal 3 and the interior of thefloating stator 4 forms a spherical interface 11. O-ring channels 15 ando-rings 7 are disposed to cooperate with said radiused surface 3 a ofsaid labyrinth seal 3 to seal (or trap) fluid migration through, betweenand along engaged labyrinth seal 3 and floating stator 4 whilemaintaining spherical interface 11 which allows limited relativerotational movement (articulation) between labyrinth seal 3 and floatingstator 4. O-ring channels 15, as shown, are machined into the floatingstator 4 and positioned at the spherical interface 11 with labyrinthseal 3. O-ring channels 15 are annular and continuous in relation tolabyrinth seal 3. The o-ring channel 15 and o-ring 7 may also be placedin the labyrinth seal 3 adjacent the spherical interface 11. O-rings 7should be made of materials that are compatible with both the product tobe sealed and the preferred sealing fluid chosen. O-ring channels 15 ando-rings 7 are one possible combination of sealing means that may be usedwithin the shaft seal assembly 25 as recited in the claims.Strategically placed anti-rotation pin(s) 12 inserted into anti-rotationgrooves 10 limit relative rotational movement between labyrinth seal 3and floating stator 4. A plurality of anti-rotation grooves 10 and pins12 may be placed around the radius of the shaft 1. If the shaft sealassembly 25 is used in combination with a sealing fluid, strategicanti-rotation pins 12 may be removed allowing correspondinganti-rotation grooves 10 to serve as a fluid passage through vent 9 andlubricant return 5. (See FIG. 7) Additionally, the relationship of thediameters of anti-rotation pins 12 and anti-rotation grooves 10 may beselected to allow more or less angular misalignment of the shaft 1. Asmall diameter anti-rotation pin 12 used with a large diameteranti-rotation groove 10 would allow for greater relative movement of thelabyrinth seal 3 in relation to the floating stator 4 in response toangular misalignment of shaft 1. Labyrinth seal 3 is one possibleembodiment of a sealing means that may be used adjacent to the shaft 1within the shaft seal assembly 25 as recited in the claims.

A continuous annular channel is formed within fixed stator 2 and definedby clearance 20 and 21 as allowed between the exterior of said floatingstator 4 and said interior of said fixed stator 2 of shaft seal assembly25. The annular channel of fixed stator 2 is highlighted as A-A′ in FIG.2. The annular channel of the fixed stator has interior surfaces whichare substantially perpendicular to said shaft 1. The exterior surfacesof the floating stator 4, which is substantially encompassed within theannular channel of the fixed stator 2, cooperatively engage with thefirst and second interior perpendicular faces of the fixed stator 2. Aninner annular interface is formed by the first (shaft seal assemblyinboard side) perpendicular annular channel surface of the fixed stator2 engaging with the first (inboard side) perpendicular face of thefloating stator 4. An outer annular interface is formed by the second(shaft seal assembly outboard side) perpendicular annular interiorchannel surface of the fixed stator 2 engaging with the second (outboardside) perpendicular face of the floating stator 4. O-ring channels 19and o-rings 13 disposed therein cooperate with the surfaces of floatingstator 4 which are in perpendicular to relation to shaft 1 to seal (ortrap) fluid migration between and along engaged floating stator 4 whileallowing limited relative rotational movement between floating stator 4and fixed stator 2. Floating stator 4 and fixed stator 2 are onepossible embodiment of cooperatively engaged sealing means that may beused in combination with labyrinth seal 3 within the shaft seal assembly25 as recited in the claims.

O-ring channels 19 are annular and continuous in relation to shaft 1.The o-ring channels 19 and o-rings 13 may be placed in the body of thefloating stator 4 instead of the fixed stator 2 (not shown) but must beplaced in similar proximal relation. O-rings 13 should be made ofmaterials that are compatible with both the product to be sealed and thepreferred sealing fluid chosen. O-ring channels 19 and o-rings 13 areone possible combination of sealing means that may be used within theshaft seal assembly 25 as recited in the claims.

Strategically placed anti-rotation pin(s) 8 inserted into anti-rotationgroove(s) 16 limit both relative radial and rotational movement betweenfloating stator 4 and interior side of fixed stator 2. A plurality ofanti-rotation grooves 16 and pins 8 may be placed around the radius ofthe shaft 1. The relationship of the diameters of anti-rotation pins 8and anti-rotation grooves 16 may also be selected to allow more or lessangular misalignment of the shaft. A small diameter anti-rotation pin 8and large diameter fixed stator anti-rotation groove allow for greaterrelative movement of the labyrinth seal 3 in response to angularmisalignment of shaft 1.

The labyrinth pattern seal grooves 14 may be pressure equalized byventing through one or more vents 9. If so desired, the vents may besupplied with a pressurized sealing fluid to over-pressurize thelabyrinth area 14 and shaft seal clearance 6 to increase the efficacy ofshaft seal assembly 25. A spherical interface 11 between the labyrinthseal 3 and the floating stator 4 allow for angular misalignment betweenthe shaft 1 and fixed stator 2. O-ring channels 19 are annular with theshaft 1 and, as shown, are machined into the fixed stator 2 andpositioned at the interface between the fixed stator 2 and floatingstator 4. O-ring channel 19 may also be placed in the floating stator 4for sealing contact with the fixed stator 2.

FIG. 3A illustrates seal-shaft integrity during angular and radial shaftalignment. This view highlights the alignment of the axial face 17 ofthe labyrinth seal 3 and the axial face 18 of the floating stator 4.Particular focus is drawn to the alignment of the axial faces 17 and 18at the spherical interface 11 between the floating stator 4 andlabyrinth 3. FIG. 3B illustrates the shaft-seal integrity during angularand radial shaft alignment at the surface opposite that shown in FIG.3A. This view highlights the alignment of the axial faces 17 and 18 oflabyrinth seal 3 and floating stator 4, respectively, for the oppositeportion of the shaft seal assembly 25 as shown in FIG. 3A. Thosepracticed in the arts will appreciate that because the shaft 1 and shaftseal assembly 25 are of a circular shape and nature, the surfaces areshown 360 degrees around shaft 1. Again, particular focus is drawn tothe alignment of the axial faces 17 and 18 at the spherical interface 11between the labyrinth seal 3 and floating stator 4. FIGS. 3A and 3B alsoillustrate the first defined clearance 20 between the floating stator 4and the fixed stator 2 and the second defined clearance 21 between thefloating stator 4 and fixed stator 2 and opposite the first definedclearance 20.

In FIGS. 2, 3, 3A and 3B, the shaft 1 is not experiencing radial,angular or axial movement and the width of the defined clearances 20 and21, which are substantially equal, indicate little movement ormisalignment upon the floating stator 4.

FIG. 4 is an exterior end view of the shaft seal assembly 25 with therotatable shaft 1 misaligned therein. FIG. 5 is a sectional view of thefirst embodiment of the shaft seal assembly 25 as shown in FIG. 3 withboth angular and radial misalignment of the shaft 1 applied. The shaft 1as shown in FIG. 5 is also of the type which may experience radial,angular or axial movement relative to the fixed stator 2 portion of theshaft seal assembly 25.

As shown at FIG. 5, the defined radial clearance 6 of labyrinth seal 3with shaft 1 has been maintained even though the angle of shaftmisalignment 31 has changed. The shaft 1 is still allowed to move freelyin the axial direction even though the angle of shaft misalignment 31has changed. The arrangement of the shaft seal assembly 25 allows thelabyrinth seal 3 to move with the floating stator 4 upon introduction ofradial movement of said shaft 1. The labyrinth seal 3 and floatingstator 4 are secured together by one or more compressed o-rings 7.Rotation of the labyrinth seal 3 within the floating stator 4 isprevented by anti-rotation means which may include a screws, pins orsimilar devices 12 to inhibit rotation. Rotation of the labyrinth seal 3and floating stator 4 assembly within the fixed stator 2 is prevented byanti-rotation pins 8. The pins as shown in FIGS. 3, 3A, 3B, 5, 6 and 7are one means of preventing rotation of the labyrinth seal 3 andfloating stator 4, as recited in the claims. Lubricant or other media tobe sealed by the labyrinth seal 3 may be collected and drained through aseries of one or more optional drains or lubricant return pathways 5.The labyrinth seal 3 may be pressure equalized by venting through one ormore vents 9. If so desired, the vents 9 may be supplied withpressurized air or other gas or fluid media to over-pressurize thelabyrinth seal 3 to increase seal efficacy. The combination of closetolerances between the cooperatively engaged mechanical portions of theshaft seal assembly 25 and pressurized sealing fluid inhibit product andcontaminate contact with the internals of the shaft seal assembly 25.The spherical interface 11 between the labyrinth seal 3 and the floatingstator 4 allow for angular misalignment between the shaft 1 and fixedstator 2. O-ring channel 19 and o-ring 13 disposed therein cooperatewith the opposing faces of the floating stator 4, which aresubstantially in perpendicular relation to shaft 1, to seal (or trap)fluid migration between and along engaged floating stator 4 whileallowing limited relative radial (vertical) movement between stator 4and fixed stator 2.

FIG. 5A illustrates seal-shaft integrity allowed by the shaft sealassembly 25 during angular and radial shaft misalignment. This viewhighlights the offset or articulation of the axial faces 17 of thelabyrinth seal in relation the axial faces 18 of the floating stator 4for a first portion of the shaft seal assembly 25. Particular focus isdrawn to the offset of the axial faces 17 and 18 at the sphericalinterface 11 between labyrinth seal 3 and floating stator 4.

FIG. 5B illustrates seal-shaft integrity for a second surface, oppositethe first surface shown in FIG. 5A, during angular and radial shaftmisalignment. This view highlights that during misalignment of shaft 1,axial faces 17 and 18, of the labyrinth seal 3 and floating stator 4,respectively, are not aligned but instead move (articulate) in relationto each other. The shaft to seal clearance 6 is maintained in responseto the shaft misalignment and the overall seal integrity is notcompromised because the seal integrity of the floating stator 4 to fixedstator 2 and the floating stator 4 to labyrinth seal 3 are maintainedduring shaft misalignment. Those practiced in the arts will appreciatethat because the shaft 1 and shaft seal assembly 25 are of a circularshape and nature, the surfaces are shown 360 degrees around shaft 1.

FIGS. 5A and 5B also illustrate the first clearance or gap 20 betweenthe floating stator 4 and the fixed stator 2 and the second clearance orgap 21 between the floating stator 4 and fixed stator 2 and opposite thefirst clearance or gap 20.

In FIGS. 4, 5, 5A and 5B, the shaft 1 is experiencing radial, angular oraxial movement during rotation of the shaft 1 and the width of the gapsor clearances 20 and 21, have changed in response to said radial,angular or axial movement. (Compare to FIGS. 3, 3A and 3B.) The changein width of clearance 20 and 21 indicate the floating stator 4 has movedin response to the movement or angular misalignment of shaft 1. Theshaft seal assembly 25 allows articulation between axial faces 17 and18, maintenance of spherical interface 11 and radial movement at firstand second clearance, 20 and 21, respectively, while maintaining shaftseal clearance 6.

FIG. 6 is a sectional view of a second embodiment of the shaft sealassembly 25 as shown in FIG. 2 for over-pressurization with alternativelabyrinth seal pattern grooves 14. In this figure the labyrinth sealpattern grooves 14 are composed of a friction reducing substance such aspolytetrafluoroethylene (PTFE) that forms a close clearance to the shaft1. PTFE is also sometimes referred to as Teflon® which is manufacturedand marketed by Dupont. PTFE is a plastic with high chemical resistance,low and high temperature capability, resistance to weathering, lowfriction, electrical and thermal insulation, and “slipperiness.” The“slipperiness” of the material may also be defined as lubricous oradding a lubricous type quality to the material. Carbon or othermaterials may be substituted for PTFE to provide the necessary sealingqualities and lubricous qualities for labyrinth seal pattern grooves 14.

Pressurized sealing fluids are supplied to over-pressurize thelubricious labyrinth pattern 26 as shown in FIG. 6. The pressurizedsealing fluids make their way into the annular groove 23 of the throttle26 through one or more inlets. Throttle 26 is also referred to as “analignment skate” by those practiced in the arts. Throttle 26 allows thelabyrinth seal 3 to respond to movement of the shaft caused by themisalignment of the shaft 1. The pressurized sealing fluid escapes pastthe close clearance formed between the shaft 1 and labyrinth seal 3having throttle 26. The close proximity of the throttle 26 to the shaft1 also creates resistance to the sealing fluid flow over the shaft 1 andcauses pressure to build-up inside the annular groove 23. Floatingannular groove 27 in cooperation and connection with annular groove 23also provides an outlet for excess sealing fluid to be “bled” out ofshaft seal assembly 25 for pressure equalization or to maintain acontinuous fluid purge on the shaft sealing assembly 25 duringoperation. An advantage afforded by this aspect of the shaft sealingassembly 25 is its application wherein “clean-in place” product sealdecontamination procedures are preferred or required. Examples wouldinclude food grade applications.

FIG. 7 illustrates shaft seal assembly 25 with the anti-rotation pin 12removed to improve visualization of the inlets. These would typicallyexist, but are not limited to, a series of ports, inlets or passagesabout the circumference of the shaft seal assembly 25. FIG. 7 also showsthe shape and pattern of the labyrinth seal 3 may be varied. The shapeof throttles 26 may also be varied as shown by the square profile shownat throttle groove 22 in addition to the circular-type 26. Also notethat where direct contact with the shaft 1 is not desired, the shaftseal assembly 25 be used in combination with a separate sleeve 24 thatwould be attached by varied means to the shaft 1.

FIG. 8 shows that another embodiment of the present disclosure whereinthe shaft seal assembly 25 has been affixed to a vessel wall 34. Theshaft seal assembly 25 may be affixed to vessel wall 34 throughsecurement means such as mounting bolts 33 to ensure improved sealingwherein shaft 1 is subjected to angular misalignment. The mounting bolts33 and slots (not numbered) through the shaft seal assembly 25 exteriorare one means of mounting the shaft seal assembly 25, as recited in theclaims.

Having described the preferred embodiment, other features of the presentinvention will undoubtedly occur to those versed in the art, as willnumerous modifications and alterations in the embodiments of theinvention illustrated, all of which may be achieved without departingfrom the spirit and scope of the invention.

1. A method for maintaining a seal around the periphery of a rotatableshaft during misalignment of said shaft, said method comprising thesteps of: a. securing a fixed stator to a housing, wherein said fixedstator is formed with an annular groove along the radial interiorsurface thereof; b. positioning a shaft sealing member within saidannular groove of said fixed stator, wherein said shaft sealing membermay move radially in said annular groove; and c. configuring said shaftsealing member with a floating stator and a labyrinth seal, wherein saidfloating stator and said labyrinth seal have a semi-spherical interfacetherebetween.
 2. The method according to claim 1 wherein said annularchannel in said fixed stator and said shaft sealing member are furtherdefined so that said annular channel fixes the axial position of saidshaft sealing member.
 3. A method for allowing shaft misalignment withina shaft seal assembly, said method comprising the steps of: a. securinga fixed stator of said shaft seal assembly to a housing, wherein saidfixed stator is formed with an annular groove along the radial interiorsurface thereof; b. positioning a shaft sealing member of said shaftseal assembly within said annular groove of said fixed stator, whereinsaid shaft sealing member may move radially in said annular groove; c.configuring said shaft sealing member with a floating stator and alabyrinth seal, wherein said floating stator is formed with a concaveradially interior surface and said labyrinth seal is formed with aconvex radially exterior surface; d. allowing said shaft to moveradially via the relative positions of said fixed stator and said shaftsealing member; and e. allowing said shaft to move angularly via theinterface between said flating stator and said labyrinth seal.